1. Field of the Invention
The invention relates to the collection of body fluid and transporting it to detecting members for determining certain aspects such as blood chemistry.
2. Description of Related Art
Treatment of diabetes requires frequent monitoring of levels of blood glucose. This is traditionally done in a series of steps involving the preparation of a lancing device, preparation of a glucose meter, lancing a finger, transporting the resulting blood drop to the meter, and finally obtaining a blood glucose reading.
Lancing devices are known in the medical health-care products industry for piercing the skin to produce blood for analysis. Biochemical analysis of blood samples is a diagnostic tool for determining clinical information. Many point-of-care tests are performed using capillary whole blood, the most common being monitoring diabetic blood glucose level. Other uses for this method include the analysis of oxygen and coagulation based on Prothrombin time measurement. Typically, a drop of blood for this type of analysis is obtained by making a small incision in the fingertip, creating a small wound, which generates a small blood droplet on the surface of the skin.
Early methods of lancing included piercing or slicing the skin with a needle or razor. Current methods utilize lancing devices that contain a multitude of spring, cam and mass actuators to drive the lancet. These include cantilever springs, diaphragms, coil springs, as well as gravity plumbs used to drive the lancet. Typically, the device is pre-cocked or the user cocks the device. The device is held against the skin and mechanically triggers the ballistic launch of the lancet. The forward movement and depth of skin penetration of the lancet is determined by a mechanical stop and/or dampening, as well as a spring or cam to retract the lancet. Spontaneous blood droplet generation is dependent on reaching the blood capillaries and venuoles, which yield the blood sample.
As lancing devices have become more advanced, so have the device used to measure the glucose levels in the blood samples. These analyte measurement devices now operate using increasing lower volumes of blood sample. Some of these analyte sensors are designed for use with lancing devices that create smaller wounds, which is beneficial in that there is less pain and tissue damage, but also provide less blood to work with. As the required amount of blood decreases, it becomes increasing important to guide the ever shrinking volumes of blood towards the sensor in an efficient manner that does not waste the small volumes of blood.